Data storage utilization is continually increasing, causing the proliferation of storage systems in data centers. Monitoring and managing these systems require increasing amounts of human resources. Organizations often operate reactively, taking action only when systems reach capacity or fail, at which point performance degradation or failure has already occurred.
For example, hard disk failures fall into one of two basic classes: predictable failures; and unpredictable failures. Predictable failures result from slow processes, such as mechanical wear and gradual degradation of storage surfaces. Monitoring can determine when such failures are becoming more likely. However, unpredictable failures happen suddenly and without warning and are mainly due to frequent data operations that exceed operational capacity of the hard disk. Therefore when a hard disk actually fails during an unpredictable failure, the data is lost from the hard disk and is no longer accessible to a client device for a certain period of time.